Case IH 19627 – Engine Control Module (ECM) / EDC (Electronic Diesel Control): Over boost deviation at P3 too high in Pressure charger regulator

This code indicates that the engine's turbocharger is producing a boost pressure (measured at point P3, typically the intake manifold) that exceeds the maximum safe limit commanded by the engine control system. When the actual boost pressure spikes above the calibrated threshold for a set duration, the system triggers this code to protect the engine from catastrophic over-pressurization.

• Tier 4b
• Steiger
• Magnum
• Puma
• Maxxum
• Farmall
• Axial-Flow
• STM N Series Loaders
• SR-series skid steers
• SR175
• F-series wheel loaders
• 121F
• 221F

1. 1

   Scan for Related Codes: Check the ECM for accompanying codes related to the MAP (Manifold Absolute Pressure) sensor or the wastegate control solenoid (e.g., open/short circuit codes), which can pinpoint the electrical failure.

2. 2

   Live Data Monitoring: Use the Case IH Electronic Service Tool (EST) or an OBD scanner to monitor live boost pressure versus commanded target boost under load.

3. 3

   Sensor Verification: With the engine off (Key On, Engine Off), verify that the MAP/Boost pressure sensor reading matches the ambient barometric pressure. If it reads artificially low, the ECM will overwork the turbo to compensate, causing an actual overboost.

4. 4

   Wastegate Actuation Test: Inspect the turbocharger wastegate actuator rod and linkage. Attempt to move it manually or with a vacuum/pressure pump to ensure it is not physically seized or binding.

5. 5

   Solenoid & Wiring Check: Test the boost control solenoid (wastegate solenoid) for proper resistance and verify that the wiring harness is free of corrosion, shorts, or breaks.

6. 6

   Inspect Hoses: Check the wastegate control hoses for blockages, kinks, or splits that would prevent the solenoid from venting pressure to the wastegate.

1. 1

   Address Sensor Faults

   If the MAP/Boost sensor failed the KOEO (Key On, Engine Off) test or is heavily fouled with soot/carbon, remove and clean it. If readings remain out of range, replace the sensor.

2. 2

   Free or Replace the Wastegate

   If the wastegate linkage is stuck closed (preventing exhaust gases from bypassing the turbine), apply penetrating oil and gently work the linkage free. If the internal wastegate flap is seized inside the exhaust housing, the turbocharger assembly will need to be removed and rebuilt or replaced.

3. 3

   Replace the Boost Control Solenoid

   If the wastegate moves freely but the solenoid fails to command it open during bench testing (or has an internal electrical short), replace the boost control solenoid.

4. 4

   Clear and Retest

   Once the faulty component is replaced, clear the 19627 fault code using the diagnostic tool. Test drive the machine under a heavy working load to verify that the boost pressure tracks accurately with the ECM's commanded parameters without spiking.